Some months ago I made some experiments with Xen and I succeeded to install and run Windows XP as a guest using Xen 3.0. In that case Windows was located in a single file and was installed through Xen.
My purpose now is to make Xen running an already installed Windows from its own partition. Just to be more specific, this is my machine configuration:

Ubuntu Dapper Drake 6.06 is located on a SATA disk, set as first boot disk

Windows XP is located on a EIDE disk, set as second boot disk

Dual boot is made by grub

I want to log into linux and run my existing Windows XP from its own partition on the EIDE disk.

I am coming from a bloody week of wrestling against packages, bugs and "make world"s trying to run Xen in Ubuntu 6.06 amd64 on an AM2 3800+ and to make a Windows XP Pro domU.
I searched on the web some resources that would explain how to run Windows on Xen and I found some very good tutorial that unfortunately don't fit exactly my configuration and my purpose. These are the sites I took as a basis for my setup: